In this tutorial we learn how elements of an RVec can be easily sorted and selected.
import ROOT
from ROOT.VecOps import RVec, Argsort, Take, Sort, Reverse
v1 = RVec("double")(3)
v1[0], v1[1], v1[2] = 6, 4, 5
v2 = sorted(v1)
print("Sort vector {}: {}".format(v1, v2))
v2 = Sort(v1);
print("Sort vector {}: {}".format(v1, v2))
v2 = Reverse(v1);
print("Reverse vector {}: {}".format(v1, v2))
v2 = Argsort(v1)
print("Indices that sort the vector {}: {}".format(v1, v2))
v3 = RVec("double")(3)
v3[0], v3[1], v3[2] = 9, 7, 8
v4 = Take(v3, v2)
print("Sort vector {} respective to the previously determined indices: {}".format(v3, v4))
v2 = Take(v1, 2)
v3 = Take(v1, -2)
print("Take the two first and last elements of vector {}: {}, {}".format(v1, v2, v3))
v2 = Reverse(Take(Sort(v1), -2))
print("Sort the vector {}, take the two last elements and reverse the selection: {}".format(v1, v2))
- Date
- August 2018
- Author
- Stefan Wunsch
Definition in file vo004_SortAndSelect.py.